Delegate user moderation

[Jonne]

I have looked around a bit for something similar to what I want but haven´t found anything matching my demands. I might have overlooked some hack so please tell me if this is already out.

What I would like:
Since I as an admin don´t have time to moderate every usergroup the needs a new user I would like to delegate this on userlevel, not grouplevel.
Users of my choise should have an extra option in their info that says "Can add users". This function should work in the following way:

Me as an admin chooses a handful of users that can add users to usergroups. The "useradmins" aren´t allowed to do anything else in the Admin CP. Only add users to excisting usergroups.

The reason I want this on userlevel and not grouplevel is that all of these useradmins will have different access to different forums and therefor I don´t want them all in the same usergroup.

Hope someone can help me ease my workload a bit with this.